How big is a 30-degree angle? You can construct an equilateral triangle with
dividers and straightedge, then cut it in half. From this you get 2 triangles each
with a 30-degree angle. Another way to do it is shown in the following
illustration. With dividers and straightedge, construct line BC equal
to AB. Draw an arc D with radius equal to AB centered on point C. From point
B construct another arc E with the same radius, intersecting D at point F. With
straightedge, draw lines CF and AF. Triangle ACF will have a 30-degree angle,
a 60-degree angle, and a right angle.

We need a mechanism to move the reflectors slowly, tracking the sun. I estimate
that a reflector weighs about a pound since it is made of cardboard and aluminum
foil. If we put a full 5-gallon bucket of water on one side of a pendulum
and a half-full bucket on the other side, then I think
that would give enough force to lift the reflectors by pulling on a string or
something. The pendulum is about 3 feet long, suspended on a fulcrum
about 4 feet above the ground. The pendulum supports a rigid platform
about 4 feet long. Fasten the buckets to opposite ends of the platform.